how to make an operator toggle?
An operator is not a property.

Setting the  toggle behaviour for a Boolean property's layout, changes the markup to a button look, rather than a checkbox As with the checkbox it changes  when setting from True to False or vice versa.

An operator layout is rendered as a button which calls the operator, rather than setting a property.

Code can be attached for  when a boolean property is updated.  See example here https://blender.stackexchange.com/a/147144/15543